Thermal Control for Cookware

PROBLEM: Unless you are using an electric skillet, controlling and maintaining constant temperature of cookware on a conventional stove can be very difficult at best, requiring constant attention, especially when frying in oil as the heat load changes constantly. Also, low-temperature cooking (e.g., eggs, candies, sauces, etc.), requires precision temperature control and very difficult to accomplish on a conventional stove.

SOLUTION: A wireless RF (Radio Frequency) Tag and embedded thermal sensor used to read and control the temperature of the cookware’s cooking surface. The host controller (stove) queries the RF tag to obtain the temperature and adjusts the heating element to maintain a constant temperature (see Figures 1 and 2)

The system is composed of two main parts: 1) RF Interrogator and Interface module that containing a microprocessor to handle both communications with the main controller and with the embedded RF Tag located in the cookware. The interrogator module could have more than one control bus to accommodate the needs/wants of the oven/stove manufactures, e.g., analog output, serial data, or Ethernet port,

2) RF Tag and interface circuitry is embedded in the cookware handle and powered by an RF signal emitted by the interrogator which also powers an analog-to-digital converter that interfaces with the thermal sensor located in the heat conducting material. When polled by the host, the microprocessor transmits a response signal back to the Interrogator module.

The RF Tag, interface circuitry, and thermal sensor would be hermetically sealed in the handle, have no moving parts, not require batteries, and be dishwasher safe. Control knobs on the stove would have dual scales, temperature and Low-to-High scales to allow both conventional operation and thermal control, i.e., setting the temperature set-point. Indicator lights would tell the operator the status of the RF communication, control mode, and /or error flags.

MARKETING and STANDARDIZATION: If the interface standards and communication protocols were standardized, both the appliance and cookware manufactures could benefit by offering “Stove-top Thermal Control” features that are universally compatible. New markets could be created for those who desire these features, which could be offered as an option at purchase, or added in the future. A variety of manufactures could offer cookware with embedded thermal sensors as the market grows and expands.

Additional features could also be added within the main controller that enhances safety by shutting off power to heating elements that are left “on” unintentionally. A complete thermal profile could be programmed through a smart phone app, or main controller, that monitors the cooking cycle. How many times has the question been asked after leaving home, “Did we turn off the stove?” The status could be checked using the phone app and the stove could be remotely turned off.